Jealous of your friends with their fancy Lytro cameras that can refocus the image after the shot has been taken? Here is an easy way to make your existing camera deliver a similar result.

The Lytro works in a different way to a traditional camera by capturing all the directions of light and creating a 3D-like map of the finished image. This lets you change the position of focus after the shot has been taken, rather than pre-focusing and capturing the plane like a conventional camera.

The clever folk at The Chaos Collective have come up with a novel way of creating a similar effect using any regular camera that has HD video capture and manual focus. By first experimenting with taking a series of still images at different focus points, they could then select the exact point where focus was desired — after the fact.

Then they realised that a sequence of images like this could more easily be obtained with a video, and came up with a tool that feeds footage into a 20x20 grid with 400 selectable regions.

To start playing with this yourself, all you need to do is mount the camera on a steady surface or on a tripod. Start filming video and move the focus from foreground to background, and ideally, shoot with a wide maximum aperture. Then, feed your footage into this tool, which will automatically create a depth-of-field changeable image.